/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.cmd;

import java.io.Serializable;

import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.ActivitiObjectNotFoundException;
import org.activiti.engine.compatibility.Activiti5CompatibilityHandler;
import org.activiti.engine.impl.interceptor.Command;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.util.Activiti5Util;
import org.activiti.engine.runtime.Execution;

/**


 */
public class GetExecutionVariableCmd implements Command<Object>, Serializable {

  private static final long serialVersionUID = 1L;
  protected String executionId;
  protected String variableName;
  protected boolean isLocal;

  public GetExecutionVariableCmd(String executionId, String variableName, boolean isLocal) {
    this.executionId = executionId;
    this.variableName = variableName;
    this.isLocal = isLocal;
  }

  public Object execute(CommandContext commandContext) {
    if (executionId == null) {
      throw new ActivitiIllegalArgumentException("executionId is null");
    }
    if (variableName == null) {
      throw new ActivitiIllegalArgumentException("variableName is null");
    }

    ExecutionEntity execution = commandContext.getExecutionEntityManager().findById(executionId);

    if (execution == null) {
      throw new ActivitiObjectNotFoundException("execution " + executionId + " doesn't exist", Execution.class);
    }
    
    if (Activiti5Util.isActiviti5ProcessDefinitionId(commandContext, execution.getProcessDefinitionId())) {
      Activiti5CompatibilityHandler activiti5CompatibilityHandler = Activiti5Util.getActiviti5CompatibilityHandler(); 
      return activiti5CompatibilityHandler.getExecutionVariable(executionId, variableName, isLocal);
    }

    Object value;

    if (isLocal) {
      value = execution.getVariableLocal(variableName, false);
    } else {
      value = execution.getVariable(variableName, false);
    }

    return value;
  }
}
